Taxonomy Notes

There is considerable variation in this species, especially with regard to the amount of blue scaling on the upperside of the female. This variation has resulting a number of named subspecies and forms, although only the nominate species is recognised here.

• Verity (1919) described the English race as ssp. brittanorum, with a type locality of Cuxton in Kent. It was said to differ from the nominate subspecies in the greater amount of blue and smaller and less vivid lunules in the female, and a darker underside that is less frequently tinged with fulvous in the male, the black dots on the underside also being smaller. The description is to be found under Agriades thetis, an earlier scientific name for the Adonis Blue.
• Verity (1919) also singled out a particular race from Ventnor on the Isle of Wight, which he named ssp. vestae, where the adults were small, the male appearing more silvery and with, in most cases, a series of premarginal black dots, and the female with greatly reduced, sometimes absent, orange lunules on the upperside which are very pale on the underside of both sexes. The underside of both sexes is also very dark.
• Verity (1934) also described f. antebrittanorum to represent the Spring generation of the English race brittanorum which, according to Verity, is separable by androconial differences.

Ochsenheimer (1808) described the spring generation of P. daplidice as f. bellidice. The nominate form, f. daplidice, is used to describe the summer generation.

Zeller (1847) described the summer generation of A. agestis as f. aestiva, having a deep brown-grey underside.

Oberthür (1910) described the English race of Common Blue as ssp. tutti. In comparison with the continental race, the English race is said to have less rounded forewings that are lengthened, a male underside that is a deeper grey in tint, and uppersides that have a more transparent blue and pink sheen. Females are generally blue with orange marginal lunules punctuated by black, especially on the hindwings, and a tendency for the colour to lighten to white near the apex of the forewings. Oberthür came to his conclusions based on 150 specimens from North Scotland, Rannoch, Cheshire, North Devon, the New Forest, North Kent, Folkestone, Dover, Glengariff and County Kerry in Ireland, and from various collections.

Graves (1930b) also described f. postclara of ssp. mariscolore that is used to represent the second generation that occurs in some parts of Ireland. In comparison with the first generation, both sexes have more tapered forewings and are slightly smaller. The male upperside is brighter and the underside of a lighter grey. The female upperside is paler at the apex of the forewings and the submedial area of the hindwings. The female underside has less metallic blue-green scaling on the bases of the hindwings.

Historically, several authorities have referred to f. scotica, defined in Watkins (1923), that is not recognised in current taxonomy. This form differs from the nominate form in that individuals are larger in size have much heavier black markings on both upper and undersides, especially in the female, and the underside has a darker green flush, with more prominent silver spots on both fore and hindwings. Different authorities described different distributions of scotica. Dennis (1977) says "The most extreme development of the morph is found in the Outer Hebrides, especially on Pabbay (Barra group), south Rona, north Raasay and on Orkney. Subspecies scotica has also been described by Heslop-Harrison for Scalpay, Soay, Rhum, Eigg, Canna and Coll, but everywhere in addition to specimens showing extreme development, others transitional to aglaia are found". The most recent analysis is given in Thomson (1980). Riley (2007) suggests that this form is found in Scotland (apart from southern localities), Ireland (where it is the only form found) and the Isle of Man. However, Riley's inclusion of Ireland is questioned by Nash (2012) who assigns all Irish specimens to ssp. aglaja. Thomson (1980), Emmet (1990), Riley (2007) and Nash (2012) elevate the aglaja forms to subspecific status. The counties where scotica was thought to be found, as mentioned by Thomson (1980), are shaded green in the image below.

Verity (1923) names the English race ssp. parvifulvior, comparing it with the race fulvior (Rocci, 1905) which is larger in size and shows extensive warm toned ground colour: "A series from Belstead Wood, near Ipswich, is markedly fulvior and warm in tone, but of the smaller (23mm.) nymotypical lucina size. I think it will be convenient to introduce the name parvifulvior for it".

Verity (1924) uses the name f. anglorum to describe the race from England, having a darker-than-average underside. Verity (1924) also uses the name f. angliae to describe a race that is intermediate between scota and jubaris, found in England.

Heslop (1962) uses the name f. sabrinae to describe the race from the limestone Failand massif in the south of Bristol, with individuals that had outer margins on the upperside that are unusually deep in colour.

Esper (1777) described the summer generation of P. napi as f. napaeae, the figure for which shows a very plain hindwing underside, with subdued markings and only a small amount of yellow. The nominate form, f. napi, is used to describe the spring generation. Similarly, Müller & Kautz (1939) described the spring generation of the Irish subspecies, ssp. britannica, as f. britannica using the name f. irica for the summer generation.

Verity (1913b) uses ssp. britanna to describe the race found in the British Isles, based on a series taken in June in Tavistock, South Devon. This race is considered to have bands that are wider, more diffused and deep black.

Verity (1929) describes ssp. vulgoadippe for the subspecies occurring in Sweden, England and across to the Pyrenees and Austria, with a type from the New Forest. This subspecies differs in its dimensions, the intensity of the ground colour and the amount of green and red on the underside.

Fuchs (1880) described the summer generation as f. parvipuncta and summarises that, in August specimens, the fringes of the forewing are less heavily chequered, the black dots are smaller and less numerous, and the greenish blue shimmer at the base of the hindwing underside is smaller and weaker. The definition (in German) also provides a detailed description of these (and other) features. The nominate form, f. argiolus, is generally considered to represent the spring generation.

Le Chamberlain (1908) names the aberration ab. cotswoldensis of Lycaena arion, defined as "Aberration of male and female with all the wings more or less thickly sprinkled with black scales, giving it a very dusky or melanic appearance, constituting an approach to the alpine var. obscura of Professor Christ. Scarce.". Goodson & Read (1969) promote the aberration to subspecies, making ssp. cotswoldensis, since the definition clearly provides a contrast between specimens from the Cotswolds and those found in Devon and Cornwall.

Verity (1919) considered the north European individuals, including those from the British Isles, to be a separate race due to the level of melanism exhibited. He named this race septentrionalis.

Stephens (1827) is responsible for the naming of f. chariclea to describe the spring brood, although it was originally a name attributed to a new species, closely related to P. brassicae. According to Goodson & Read (1969), the name is, without question, given to a description of the spring generation of P. brassicae. f. brassicae, the nominate form, is then used to describe the summer generation.

In describing P. chariclea, Stephens makes comparisons with P. brassicae: "The chief points of discrimination between this species [P. chariclea] and the preceding insect [P. brassicae] consist in its inferior size, the dissimilar colour of the apical spot on the anterior wings above, and the integrity of its inner edge, the pale cilia with which it is fringed, and the deeper colour, and more thickly irrorated under surface of the posterior wings: which characters, taken collectively, appear fully sufficient to warrant its separation as a species, exclusively of its period of flight".

Stephens goes on to make some misinformed hypotheses of how P. chariclea could simply represent the spring brood of P. brassicae: "Now, if it be a vernal [spring] brood of Po. Brassicae alone, by what process do the colour and the shape of the markings become changed? and whence its inferior size? The first question has been answered, at least so far as regards the colour, upon the supposition that the solar rays are not sufficiently powerful at the period when the insect is produced, to produce the intense hue so conspicuous in the supposed aestival [summer] brood ... With respect to the other question - the inferiority of size - that has been answered upon the presumption that the animal diminishes in bulk from the increased period that it is supposed to continue in the pupa; that is, from September to April: whereas the aestival brood remains in that state a few days only".

The variability of this butterfly has historically given rise to several named subspecies and forms. These additional subspecies and forms are based primarily on differences in the contrast and melanism exhibited.

• Birchall (1873) describes f. hibernica to represent the Irish population and Kloet (1972) elevates this form to subspecific status. It differs from the nominate form in having a greater contrast between the orange ground colour and cream markings.
• Robson (1880) describes f. scotica to represent the populations found in Scotland and compares it with the Irish form, hibernica: "The Scotch form, Scotica, is smaller, scarcely so densely scaled, the red and yellow marks not so distinctly different, and the black, duller in hue. Both this and the Irish form often have the inner half of the red band near the hind margin, pale straw color". Huggins (1959) says that scotica is the commonest form found in Kerry, Ireland.
• Kane (1893) describes f. praeclara which "is the one most commonly met with in Ireland, having the red and central pale series very vivid in colour, and the black reticulation darker than the type" and refers to the figures shown in Hübner (1779). praeclara was considered by Harrison (1946b) to represent the populations on Tiree, Gunna, Rhum and Eigg in the Inner Hebrides, extended to Islay, Jura and "the Oban district" by Ford (1945). Huggins (1959) says that this form is found, but uncommon, in Kerry, Ireland. Goodson & Read (1969) say "The name [praeclara] covers extremely brightly coloured and contrasting examples ... It is not a name for Irish examples only, since Kane gives English localities as well as Irish for the form". Dennis (1977), however, considers praeclara to be a synonym of hibernica.
• Fruhstorfer (1916) describes ssp. anglicana to represent the population in England, which is characterised by individuals that are relatively light in colour and with less contrast. The variability of this butterfly is summed up by Johnson (1955) who observed differences between two populations near Guildford in Surrey "which were a mere quarter of a mile apart, being separated by only a small copse".
• Fruhstorfer (1916) also describes ssp. acedia to represent the population in Wales, which is characterised by males that have large and regular submedian spots that are not surrounded by black bands, and females with extensive light areas on the forewings, and lacking the black and reddish-brown areas.

Verity (1911b) uses the name ssp. scota to describe the race from the north coast of Scotland. On the underside the whitish space of the hindwings is excessively broad, its forepart extending, both on fore and hindwings, as far as the ocellus or ocelli.

Verity (1926) uses the name ssp. londinii to describe the race from southern England. The underside of the hindwings are suffused with a rich warm chestnut tinge to an extent not seen in any other race. Also, on the underside of the forewings, there is a sharp black streak that divides the wings from the costa to the second cubital nervure, showing a bolder pattern than other races.

Freyer (1852) used the name f. selenia to describe the summer generation and, until recently, ssp. insularum was recognised, as defined in Harrison (1937), but is not present in current taxonomy. This subspecies was found in north-west Scotland in several islands that make up the South Ebudes, Mid Ebudes and North Ebudes and the adjacent mainland, reaching into parts of Argyllshire, West Inverness-shire, West Ross and West Sutherland. It is somewhat brighter in colour and markings, on both upper and undersides, than the subspecies selene. Ford (1945) questions its taxonomic status: "it is perhaps doubtful if it merits a distinct name". Dennis (1977) has a similar view: "It is allegedly brighter in colour and markings on both surfaces than English B. selene, with greater contrast on the undersurface. On this basis the writer finds them difficult to separate from series collected at high altitudes in north Wales".

Zeller (1847) described the summer generation of P. rapae as f. aestiva, which is more heavily marked with black and more richly coloured. The nominate form, f. rapae, is used to describe the spring generation.

In addition to the named subspecies, Thompson (1952) identified a race that formed an altitudinal cline in Snowdonia, south-west of the river Conway, giving it the name ssp. drumensis. The single-brooded adults flew in June at high altitude above the tree line, and were large with pale prominent markings.

Fruhstorfer (1909) uses the name f. aestivalis to describe the summer generation, the spots lighter in tint and not so large as those of the spring form.

Ball (1914) uses the name f. filipluma to describe specimens of the summer generation, differentiated by their scale formation.

Verity (1911a) uses the name ssp. caledonia to describe the race from Scotland which, he says, differ in the width and intensity of the black markings and very broad marginal band. The base of the hindwing being entirely blackened.

Aside from the confusion that has historically surrounded the identification of L. sinapis, L. reali and L. juvernica, several other taxonomic names have been applied to L. sinapis.

• Hübner (1823) uses f. lathyri to describe the spring generation. f. sinapis, the nominate form, is then used to describe the summer generation.
• Verity (1916) uses f. transiens to describe the British population and mentions the distinguishing features: "The British race is quite similar in both generations to the nymo-typical one; it is a little smaller than the one from the South of Europe; a careful comparison also shows that the dark bands on the underside of the hindwings in the summer broods are more diffused than in Italian specimens, thus differing a little less from the spring brood than in the latter region; form transiens, mihi; "types" from the New Forest in July".